Final answer:
Galvanized iron, copper, PVC, and CPVC are materials used for water pipes. Copper is also a common material for electrical wiring due to its excellent conductivity and physical properties. Other materials mentioned are not suitable for electrical or gas pipes.
Step-by-step explanation:
Galvanized iron, copper, PVC, and CPVC have all been used for water pipes. Copper, due to its high electrical conductivity, tensile strength, and ductility, is frequently used in electrical wiring. While PVC and CPVC are commonly utilized in plumbing for water delivery, they are not suitable for electrical wiring or gas pipes. For example, galvanized iron is often protected via cathodic protection to prevent rusting in water pipes.